**EXHIBIT 21**

**DRSTECHNOLOGIES, INC.**

**SUBSIDIARIESOF THE COMPANY AS OF MARCH 31, 2006**

| **SUBSIDIARY**                                      | ** ** | ** **                     | ** ** | **STATE OR COUNTRY   OF FORMATION** |
|-----------------------------------------------------|------------|--------------------------------|------------|-----------------------------------------------|
| NAI Technologies, Inc.                              |       | New York                       |
| DRS Electronic Systems, Inc.                        |       | Delaware                       |
| DRS Technical Services, Inc.                        |       | Delaware                       |
| DRS Surveillance Support  Systems, Inc.             |       | Delaware                       |
| DRS Technologies Canadian  Capital Corporation      |       | Canada (Nova Scotia) |
| DRS Technologies Capital  Company, Inc.             |       | Canada (Nova Scotia)           |
| DRS Tactical Systems, Ltd.                          |       | United Kingdom                 |
| DRS Systems Management  Corporation                 |       | Delaware                       |
| Laurel Technologies Partnership                     |       | Delaware                       |
| DRS Power & Control  Technologies, Inc.    |       | Delaware                       |
| DRS Electric Power Technologies,  Inc.              |       | Delaware                       |
| DRS Power Technology, Inc.                          |       | Delaware                       |
| DRS Tactical Systems, Inc.                          |       | Florida                        |
| DRS Engineering Development  Labs, Inc.             |       | Ohio                           |
| DRS Signal Technologies, Inc.                       |       | Ohio                           |
| DRS Signal Recording  Technologies, Inc.            |       | Maryland                       |
| DRS Optronics, Inc.                                 |       | Delaware                       |
| DRS Sensors & Targeting  Systems, Inc.     |       | Delaware                       |
| DRS FPA, Inc.                                       |       | Delaware                       |
| DRS Infrared Technologies, LP                       |       | Delaware                       |
| DRS Unmanned Technologies, Inc.                     |       | Delaware                       |
| DRS Data & Imaging  Systems, Inc.          |       | Delaware                       |
| DRS Data & Imaging  Systems Limited        |       | United Kingdom                 |
| DRS Hadland Ltd.                                    |       | United Kingdom                 |
| DRS Technologies Canada, Inc.                       |       | Delaware                       |
| DRS Technologies Canada Company                     |       | Canada (Nova Scotia)           |
| DRS Communications Company LLC                      |       | Delaware                       |
| MSSC Company                                        |       | Pennsylvania                   |
| Tech-Sym Corporation                                |       | Nevada                         |
| DRS Test & Energy  Management, Inc.        |       | Delaware                       |
| DRS EW & Network  Systems, Inc.            |       | Delaware                       |
| DRS Signal Solutions, Inc.                          |       | Delaware                       |
| DRS Training & Control  Systems, Inc.      |       | Florida                        |
| Integrated Defense  Technologies, Inc..        |       | Delaware                       |
| T-S Holding Corporation                             |       | Texas                          |
| DRS EW & Network  Systems (Canada) Limited |       | Canada                         |
| DRS International, Inc.                             |       | Delaware                       |
| DRS Systems, Inc.                                   |       | Delaware                       |
| Night Vision Equipment  Co., Inc.              |       | Delaware                       |
| Canopy Technologies, LLC                            |       | Delaware                       |
| DRS Tactical Systems Global  Services, Inc.    |       | Florida                        |
| Walkabout Computers UK Limited                      |       | United Kingdom                 |
| DRS Codem Systems, Inc.                        |       | Delaware                       |
| Engineered Support  Systems, Inc.              |       | Missouri                       |
| Engineered Air Systems, Inc.                   |       | Missouri                       |
| ESSI Resources, LLC                                 |       | Kentucky                       |

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| ESSIbuy.com, Inc.                          |   | Missouri              |
|-------------------------------------------------|--------|-----------------------|
| Engineered Coil Company                         |   | Missouri              |
| Air Eagle Holdings, Inc.                   |   | Missouri              |
| KECO Industries, Inc.                      |   | Ohio                  |
| Engineered Electric Co.                         |   | Missouri              |
| Engineered Systems and  Electronics, Inc.  |   | Missouri              |
| Systems & Electronics  Inc.            |   | Delaware              |
| Radian Inc.                                     |   | Delaware              |
| Universal Power  Systems, Inc.             |   | Delaware              |
| Technical and Management  Services Corporation. |   | Maryland              |
| Engineered  Environments, Inc.             |   | Ohio                  |
| 3083683 Novia Scotia Limited                    |   | Canada (Novia Scotia) |
| Pivotal Power, Inc.                        |   | Canada (Novia Scotia) |
| Prospective Computer Analysts  Incorporated.    |   | New York              |
| PCA Electronic Test Ltd.                        |   | United Kingdom        |
| Spacelink International LLC                     |   | Delaware              |
| Mobilized Systems, Inc.                    |   | Ohio                  |

 

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